Hybrid motor vehicles, electric motor vehicles and the like using batteries such as lithium-ion batteries or nickel-hydrogen batteries as power sources are known. Each of batteries of these kinds has a temperature range in which adequate input and output characteristics can be attained. If the battery is used at a temperature deviating from the temperature range, there is a possibility of a reduction in performance or a reduction in life of the battery. Therefore, batteries for hybrid motor vehicles or the like are temperature-controlled by various methods.
Patent Literature 1 discloses a temperature adjustment apparatus for adjusting the temperature of a battery for an electric motor vehicle by using a Peltier element. Patent Literature 1 discloses a control process in which when the battery is in a high-temperature condition such that the temperature of the battery exceeds a suitable temperature range, a current is caused to flow through the Peltier element so that the battery can be cooled with the Peltier element. Patent Literature 1 discloses a control process in which when the battery is in a low-temperature condition such that the temperature of the battery below the suitable temperature range, a current is caused to flow through the Peltier element so that the battery can be heated with the Peltier element.